Web Analytics RiceHigh's Pentax Blog: July 2009

Friday, July 31, 2009

K-7 Automatic Level Correction Defect and Bug

First, this user reported that the Auto Level Correction (ALC) of one of his defective K-7 units received, whenever turned on, would tilt the images by 0.5 to 1 Degree! Yes, it shows the system and function does work, but NOT correctly!


And then how the ALC could defect the AF (one of the AF points) when it is turned on, as reported by another new K-7 user (who is a very experienced Pentaxian)!


Any defect could be understood somehow and it's about poor quality control of the factory. But the above bug found seems to be true and it is needed to be fixed.

Well, I think Pentax/Hoya should serious think about how their (proven to be ineffective) beta testing programme(s) should be conducted and more competent persons should be found to do the test for them! E.g., like the above two users, one Pro and one very experienced Pentaxian without blind brand loyalty than those whom would *always* say everything from Pentax is good and perfect - asking those fanboys or merchants or just anyone without good enough technical knowledge (and more importantly to honestly report problems) to do any test (beta or not) is just a waste of time and resources! And, the manufacturer needs to bear all the serious consequences as a result, like what have been happening around the K-7 now.

K-7 Vertical Line in Images Bug Event Log and Summary

I summarise in this Blog entry for what have been documented at my Blog so far for the "discovery" of exactly the same bug of above. Actually, the bug reports by different K-7 users appear repeatedly from date to date and have never stopped.

In chronological order:-

June 24: The Vertical Line was first discovered by a careful-minded person in the pre-production picture samples of the K-7: http://ricehigh.blogspot.com/2009/06/bundle-of-new-full-size-k-7-sample-pics.html

(Click to Enlarge)

July 3: The Vertical Line was found by me (for the first time by anyone on the Internet who posted about the problem) in the *production* K-7 sample picture by a new Japanese K-7 user. As I predicted, it looked like a common bug and issue (although as usual I was bashed to death by some): http://ricehigh.blogspot.com/2009/07/strange-line-in-image-of-k-7-appears.html

(Click to Enlarge)

July 9: The Vertical Line Bug reports continued: http://ricehigh.blogspot.com/2009/07/strange-vertical-line-strikes.html

(Click to Enlarge)

July 11: A DPR user complained about the Vertical Line, which destroyed his originally should be very nice picture (plus terrible noise at ISO 400, too): http://forums.dpreview.com/forums/readflat.asp?forum=1036&thread=32370822 via http://ricehigh.blogspot.com/2009/07/adverse-user-reports-of-k-7-continue.html

(Click to Enlarge)

July 15: More and more new K-7 users found the Line and Bug Worldwide (this time reported by a German user): http://ricehigh.blogspot.com/2009/07/k-7-strange-vertical-line-repeatedly.html

July 30: A Chinese K-7 user at Hong Kong has discovered lately that his K-7 has the same Vertical Line Bug, again his pictures are nice but there is a Vertical Line in some of them! Plus, noise are no good even at ISO 200 (see the background):-

(Post in Traditional Chinese)

(Click to Enlarge)

Of course, the new Firmware 1.01 won't help even for what he has tried. Who told and tells that the FW 1.01 has this (possibly hardware) bug fixed?? Have Hoya/Pentax yet admitted the problem and offered a solution so far???

See also this nice summary on actually the FW 1.01 won't help on the Vertical Line by this smart guy who posted at my Yahoo Pentax Discussion Group:-


Obviously, the Firmware "update" is *Irrelevant*.

Well, when will Hoya/Pentax react to this real and annoying issue before it is too late for what it would destroy and hurt (1st hand sales, used market sales, users' sentiments, etc.). But one thing is for sure, if they don't find a remedy soonest, all the affected K-7 users or even potential buyers will be frustrated. And surely many potential K-7 buyers will withhold their purchasing plan.

This case is surely not isolated case as from what all we've learnt by now, possibly there are some design issues, and more possibly with the Samsung sensor and its associated hardware. The chance for poor Quality Control is still here but it is not that likely. And if the QC is as poor as that, this is yet again a very worrisome thing for Pentax/Hoya. Let's see if Pentax could come up with a new Firmware update which can *hide* the problem.

Thursday, July 30, 2009

Blog Notice: Comment Moderation Enforced in the Meantime

Owing to the stupid and silly frequent and repeated Blog attacks and spamming recently, the comment moderation is enforced in the meantime. If you have a comment to leave, please feel free to continue to do so and your post will appear after checking has been made. Different opinions really doesn't matter as long as no foul language is used and any personal attack and uncivilised behaviour are strictly prohibited.

I hereby apologise for all the inconvenience caused to all of you who really want to post on-topically. Thank you for your pardon and patience and I hope all of you whom are affected can understand.

On the other hand, without those foul language and offensive words, I am sure that this site will be more pleasant to read for those who really want to read and write.

Update (August 1st):

A New Comment System has been successfully implemented at my Blog and there will be no forced comment moderation before posting of any comment. The new system is currently used for all coming New Blog Posts or Old Posts in which there is No Discussion Started Yet. Enjoy and keep posting! :-)

Wednesday, July 29, 2009

Hypocrites/Cowards of those "Pentax" Forums

Someone made a post with links to my blog at the Photo.net's "Pentax" forum but the thread was shortly closed:-


And then today a poster at the PentaxForums has made a post about my article and discussions and my link was immediately removed by the site owner, Adam:-


Whilst from time to time I point to any sites and forums for news and posts that are relevant to Pentax and gear (and I am still doing so), I just cannot understand why those Forum owners should try to control speeches and don't allow their "members" to even just post an Internet link (of mine)!?

Those people are just hypocrites but cowards afterall. But they are just plain stupid and silly. Well, I just wish to ask: What are you "site-owner" guys are so being AFRAID of?? WHAT??

Btw, is there any free Forum for the Pentax Community. If you don't like that your voices are being suppressed at the only few Pentax Forums on the Net and there are just too much unreasonable censorship and white horror, try to join mine:-


p.s. Even the DPR allows my links, as my sites are all totally non-commercial. What are those other guys are trying to FILTER?

Update (7-30):

Here is yet again an example of excessive filtering and censorship at the PentaxForums. The poster wrote the post and it did not appear at the PentaxForums thread and thus he has re-posted it at my Yahoo Pentax Group:-


I think what the poster writes are totally legitimately and in a polite way too, which should meet the "rules" of any forum on the net. So, why delete/hide/withheld those posts? I'm afraid people these days just very love to control Freedom of Speech of others, whenever the Authorities who have the Power don't like others' opinions, which could be different or simply that they JUST do NOT want to see for some reasons! Civilised enough?

Blog Trailers - Coming New Articles or Update

1. An update to my last article on JPEG and RAW quality of K-m will be made. There will be an added comparison between PPL 3.60 (SilkyPix Engine) against the Raw Therapee 2.4 - Target time frame: within this week. (7-30: Done!)

2. A technical article on the calibration and adjustment of K-mount lenses mechanically (at the A position, applicable to Pentax SMC-A/F/FA/DFA/DA lenses) to improve precision and exposure accuracy - Target date: 1st week of August. (11-15: Done!)

3. An article on the K-m Tips and Tricks and my own "best settings" for the camera and the rationale behind - Target date: before mid-August. (9-6: Done!)

Stay tuned. And I hope I can meet the schedule. :-)

"Adverse" User Reports of K-7 Continue..

Having lurked around the DPR Pentax SLR Forum for about 3 minutes, it is not difficult to notice all those adverse reports by different new K-7 users:-

Six K-7, all Failed (Buggy and Quality Issues):


Poor IQ and noisy images as judged by a professional user:


The vertical line bug (First discovered by me and talked publicly for a production K-7) appears again and void very nice shots (as they should be):


Do note also the rather noisy image at ISO 400 only!

Short battery life, very long time to charge:


Oh, well..

I think for all those numerous issues and problems as well as the low IQ performance of the K-7, meaningless firmware updating on minor things like sesames won't help! Will it?

Monday, July 27, 2009

Ultimate APS-C Shootout: K-7 Vs 50D Vs D300 Vs A700

In the current issue of the most popular HK Digital Camera magazine (printed), the DiGi Bi-weekly, there is a full shootout on the above DSLRs:-


The same lens model was used to do all the tests, it is the Tamron A18 (18-250mm/3.5-6.3 Di II).

For specs comparison, the K-7 wins in size and weight (well, we all knew), the 50D wins in pixel count and ISO range, the D300 wins in AF system and the viewfinder. The A700 wins nothing on paper.

Btw, here is a concise summary on specs differences of the four APS-C DSLRs:-

Launch Date
Pixel Count
ISO Speed Range (Normal / Expansion)
Weight (with Battery)
AF System (Total Number of Points / Number of Crossed Points)
ISO 100-3200 / 6400
131 x 97 x 73mm
100%, 0.92X
11 / 9
ISO 100-3200 / 6400-12800
146 x 108 x 74mm
95%, 0.95X
9 / 9
ISO 100-3200 / 6400903g
147 x 114 x 74mm
100%, 0.94X
51 / 15
ISO 100-3200 / 6400768g
142 x 105 x 80mm
95%, 0.9X
11 / 1

Well, the lab tests and measurbations begin..

1. Dynamic Range Test

Test description and methodology: All cameras set at ISO 200, finest JPEG, on tripod, metering by external incident light meter, Av=f/8, shot target was Kodak Gray Scale, final images analysed by Zoner Photo Studio 11 (clipped highlights and shadows will be shown). Exposures from -2 EV to +2 EV in 1 EV step were made with with highlight and/or shadow optimisation turned off and on.

An extracted summary on the results in the Numbers of Steps Clipped for the Highlights / Shadows are as follows:-

-2 EV
0 EV
50D (Default)
1 / 7
1 / 6
3 / 0
50D (Highlight Optimisation On)
1 / 6
1 / 6
1 / 0
50D (Highlight Optimisation On with Auto Leveling)
Note: Very low contrast images were produced.
0 / 0
0 / 00 / 0
D300 (Default)
0 / 00 / 00 / 0
Active D-Lighting On: Highest
1 / 6
1 / 6
0 / 0
K-7 (Default)
1 / 0
1 / 01 / 0
K-7 (Highlight Optimisation On)
1 / 7
1 / 0
1 / 0
K-7 (Highlight Optimisation On + Shadow Compensation)
Note: All images had become rather Yellowish.
0 / 0
0 / 00 / 0
A700 (Default)
1 / 0
1 / 01 / 0
A700 (D.R.O Auto On)
1 / 01 / 01 / 0
A700 (D.R.O Advance/Manual +5)
Note: There is no significant effect regardless of the settings!
1 / 01 / 01 / 0

The editor further particularly notes that the K-7 images had large amount of noise appears when the compensation functions were turned on, but the DR results could be even worse!

2. Noise Test

Test description and methodology: The same set of test objects were shot under studio environment with different ISO speeds available for the cameras. Same aperture and exposure values are used; same WB, highest resolution and finest JPEG; All built-in compensation functions for distortion and vignetting etc. were disabled; other settings remained at factory defaults.

Cropped portions of the images obtained at the same viewing size are printed.

Results: For what I can see, the K-7's ISO 800 is a bit worse than the ISO 1600 of the 50D and the D300 (and that the 50D images seem slightly better). And, the ISO 800 images of the K-7 are still a bit worse than those of the ISO 800 of the A700. Of course, with the NR turned on, noise are suppressed at the cost of less details.

3. Auto White Balance Test

Test description and methodology: The GretagMacbeth ColorChecker was shot in Auto WB mode and ISO 200 under daylight, fluorescent and tungsten as well as an accurate 4000K light sources. The images were then imported into the Imatest and the colour accuracies were checked.

Some of the more important results on the Accuracy of Reproduced Skin Tones / Greys are summarised as follows:-


(Overall Colours)
Good / Good
Good / GoodSerious Orange Cast / Serious Orange Cast Better
Good / GoodOrange Cast / Yellow Cast
Serious Orange Cast / Serious Orange Cast Good
Magenta Cast / Blue Cast
Good / GoodSerious Purple Cast / Serious Orange Cast Good
Slight Magenta Cast / Slight Blue Cast
Slight Orange Cast / Good
Serious Orange Cast / Serious Yellow Cast Fair

4. Resolution Test

Test description and methodology: The ISO 12233 Resolution Test Chart as well as a real scene were shot; All cameras set at f/8; ISO 100; Highest Resolution; Finest JPEG; Cameras mounted on Tripod; SFR (Spatial Frequency Response) at MTF50 by Imatest were measured.

Crops of the resolution chart test shots and the real scene images are also printed (in the same viewing size).

As for the Imatest SFR figures, here they are:-

Resolution (Image Centre)
Resolution (Image Corner)
2,324 LW/PH (Line Widths Per Picture Height)
2,168 LW/PH
1,921 LW/PH1,935 LW/PH
1,893 LW/PH1,856 LW/PH
1,958 LW/PH1,904 LW/PH

The K-7, despite of having a pixel count close to that of the 50D, it loses "hands up" for both the resolutions at image centre and image corner. And, the real scene sample photo crops are obviously "soft", and so do the test chart crops.

Well, the above is *exactly* what I found previously for my own hands-on test of the K-7 (against 5D), the K-7 is just producing very soft and low resolution JPEGs even at ISO 100 (and noise control is not good as well). Too bad.. :-(

My bet is that soon when the Dpreview (DPR) resolution test and review is out, once again the K-7 will score very low in the IQ/PQ department and it will be commented as a "Soft JPEG" machine again, as usual, for what Pentax DSLRs have long been renowned for!

In fact, for the low PQ/IQ of the K-7, it is really really sad for all Pentaxians (and it actually becomes hopeless), especially for all those who are waiting for a *real* upgrade and a better body from Pentax, maybe for many years already, including me of course. With the low Image Quality of the K-7, no matter on resolution and noise level (and the AWB is not really quite as good as others as well, according to the above AWB test in the lab environment), the K-7 is really a big let-down.

At the end of the days, I just wish to ask: Without good IQ and PQ, what else is/are more important for a DSLR?? I guess one of the main culprits for the low IQ/PQ performance of the K-7 should be the new version of the Samsung sensor, which has the speed increased but not so for the image quality and noise control, but the reverse! (So, for those who are really having high hopes on the upcoming NX, my advice is don't let yourself have *high hopes*!)

Furthermore, in view of the machine/system performance, no Pentax could actually match and catch up with C and N machine guns and AF monsters anyway, as proven and verified again in this test.

I originally planned to buy the K-7 the first time I heard about it and learnt something more about its specs. But the reality and many reviews just show that it just cannot live up to the hypes Pentax/Hoya (more so by the Internet community actually) have created and its actual performance and (the low) IQ are just falling short of in many ways.

Objectively, it is really rather unwise for me to invest in this body as I am afraid that its PQ (both resolution and noise) are just even worse than the old K20D which is now still available brand new at half of the current price of the K-7 brand new (although the K20D has so many known issues and problems, too). In the meantime, I think the only model of DSLR body in the Pentax land which I could recommend is the K-m (Yes it is an entry level model, but it is the ONLY *Sensible* Choice right now, IMVHO), for which I have acted recently - I've acquired a special edition, anyway.

Besides, snowing is now all over the Pentax land for all Pentaxians worldwide in view of the ridiculous high prices of all those Pentax lenses now on sales as well as the crazy increased prices of those Pentax accessories as well. I've checked today the price of a 360FGZ flashgun has now been increased for +75% (which is just about 20% more expensive than a Canon 430EX II flashgun!) and that of the 540FGZ is now more expensive than the Canon top-of-the-line Pro usage weather-sealed 580 EXII too. I think Pentax the brand will really soon go out of business in one to two years to come (if they still do not make better products and re-establish a more sensible pricing strategy and revise all the nonsense (increased) new prices of their lenses and accessories).

Last but not least, if you are in Hong Kong, I highly recommend that you should buy the magazine (if you're interested) to see all the test pictures and results as well as more comments by the testers/editors, you can buy the magazine before August 7 (next Friday).

Sunday, July 26, 2009

K-m Battery Issue, Solution and Timing Measurbations

As for years, the AA battery issue of the Pentax DSLRs have not yet been completely resolved by Pentax, never (and forever - my bet).

There is no exception for the K-m, which now even only allows solely the use of AA type batteries and CR-V3 type cannot be inserted for what the battery compartment is designed, mechanically, since the K200D. Here is a shot about how the battery compartment is designed and made (note the protruding part inside):-

The problems of using AA NiMHs are heavy (about 110g for 4), short battery life, unstable battery power and lower camera performance.

I use Sanyo Eneloop and the battery half-depleted warning often appear after heavier power demand when using the camera. I really don't like it, or just hate it. And, four AA NiMHs which are roughly equal 110g, which are no good to carry around everywhere. For just the weight of such low performance batteries, I think it is not worth, in any sense.

But then here comes the Energizer Lithium AAs, which are bundled with the camera and is highly recommended by Pentax. Yes, they are light-weight and of high performance. But the main problem is that they are NOT Rechargeables! Cost is a concern here and more a problem for its non-environmental friendliness! Hey, men, please save the Earth!

So, can we all Pentax AA DSLR users can get the best of both worlds? I am afraid that the answer is No and Not, especially with the current line of Pentax AA battery DSLRs which do not even allow the use of CR-V3 so that even those *Regulated* CR-V3 cannot be inserted and used in any K-m and K200D.

Since I have two Regulated Rechargeable CR-V3 and a dedicated charger left from my old K100D (which can use the CR-V3 batteries), I have been thinking about to hack the batteries so that I could use the high performance Lithium-ion battery in my K-m again. But since Pentax have prohibited the use of even disposable CR-V3s for my K-m, I have been careful to think about it more and measured the battery voltage (again) for different battery types:-

- Eneloop: Maximum no-load freshly charged voltage for two: 2.5~2.6V;
- CR-V3: Maximum no-load voltage per each new battery: 3.3~3.4V;
- Energizer AA Lithium: Maximum no-load voltage for two: 3.1~3.2V;
- My Regulated RCR-V3 when freshly charged, no-load: 3.4V

Since it is just too difficult and actually non-sense to hack the K-m's battery compartment, I simply dissembled my CR-V3 and remove the part that has conflicts with the "prohibiter" of the battery compartment and re-wrapped the battery and sealed all the electrical parts with Denka Vini-Tape:-

Well, do note the above that the battery has PCB and circuitry and components inside in order to regulate the voltage down to 3.4V which is lower than the nominal voltage of 3.7 to 4.0V of the rechargeable Lithium-ion cells that are used.

But since two RCR-V3s now make up 6.8V and even disposable CR-V3s which can also have that maximum total voltage (of 6.8V also) are not "designed" to be used in the K-m, I have not been dare to insert two RCR-V3s in my K-m at the same time, as the overall voltage would be too high for the camera (The highest safe voltage limit would be 6.4V, i.e., the voltage of two new AA Lithiums). I opted not to take the risk to "overclock" my camera by that 0.4V, which maybe outside the design tolerance.

So, must I use the low voltage and low performance NiMHs in my K-m if I want rechargeables? In fact, my K-m will get the battery half-depleted warning shown for a set of four newly charged Eneloops after 100 shots and especially after high current/power is required/demanded, e.g., more AF, more LCD displaying, continuous shooting (this mode is really power hungry! Try it yourself!).

To get the best of both worlds and still make it safe enough, I mix one hacked RCR-V3 of mine and two Eneloops, so as to make up a "new" voltage of 6.0V, which is actually the idealistic value for battery voltage for all Pentax AA DSLRs! Mixing these two types batteries will not harm as:-

1. The batteries are in series but not in parallel;
2. The lower performance batteries are also rechargeables so there is no risk in being charging them up by another more powerful power source;
3. The higher internal resistance of any battery cell will limit the maximum current through the whole electrical circuit (but possibly the camera itself should be the bottle neck).

After all these hacking and voltage measurements, I still have to test the differences in performance for using different battery types and combinations, namely, I have measurebated the AF motor speed and the camera system/shutter time lag, here are the results:-

Batteries and Combination
Made-up total battery voltage (no-load)
AF Speed (See Remark 1)
Shutter Lag (See Remark 2)
4 Eneloops
1.195s (Download sound file)
121ms (Download sound file)
2 Eneloops + 1 RCR-V3
1.105s (Download sound file)116ms (Download sound file)
1 RCR-V3 + 2 AA Lithiums
1.082s (Download sound file)112ms (Download sound file)
4 AA Lithiums
1.088s (Download sound file)113ms (Download sound file)

1. The FA 43 Limited was mounted, first driven to infinity before the test, then pointed the camera to a bright sky without any pattern and let the motor ran from 00 to the nearest distance and back to 00 and the timing was measured;

2. Measured from the completion of shutter release button pressing to the time of exposure.

3. The above test was carried out in an air-conditioned room at around 24 deg. C.

Do note that the above test is carried out for freshly charged batteries and new AA lithiums from newly opened pack. The difference in performance will become more obviously shortly when the performance (actually on-load voltage) of the AA NiMHs (Eneloops - the best and most "suitable" model, already) drops very quickly after 100 shots or so and in heavier current/power demand situations.

In the meantime, I shall choose the 1 RCR-V3 + 2 Eneloop mixed rechargeable solution. Now, I have turned on the back (status) LCD of my K-m on all the time (via a Custom Function, which is actually the default setting, but power consuming) and need not to worry about battery power drainage any more.

Also, as you can see, the performance of the camera, when using the mixed rechargeable solution, is actually close to that of using solely new AA Lithiums, which is yet a good thing. It can also be noted that further increasing the battery voltage has only minimal benefit for the camera performances, for both AF speed and system/shutter time lag. So, the bottle neck and threshold is really the NiMH battery and most benefits can be obtained/seen when changed to AA Lithium (and now by only one Regulated Rechargeable CR-V3) - project completed, hacking completed! ;=D (Victory!)

p.s. IF I was the Engineer of Pentax, I would choose to use an proprietary Lithium-ion/Lithium Ploymer rechargeable solution in ALL the DSLRs - problem totally resolved and the end of the story and all problems!

Friday, July 24, 2009

K-m Olive: Sharp JPEG, Soft RAW(PPL/SilkyPix)!

The pixel peeping continues! This time is for the in-camera JPEG against RAW with the K-m Olive.

First, here is the image directly out of the camera, in the finest quality JPEG (File at around 3MB), shot in the RAW+JPEG mode (PEF):-

(Downsized only, all EXIF data preserved)

And then, the directly ("automatically") converted image from RAW using the original Pentax Photo Laboratory (Version 3.60) software, saved as the highest quality (File at around 8MB):-

(Downsized only, all EXIF data preserved)

Now, the pixel peeping begins! Here is the 200% view crop from the in-camera JPEG:-

(Click to view in full: 100% crop, simple resizing to 200% (no re-sampling), saved as 100% Jpeg with IrfanView, for easy but accurate viewing here.)

And then the 200% view crop from the PPL (with SilkyPix image engine) RAW converted JPEG:-

(Click to view in full: 100% crop, simple resizing to 200% (no re-sampling), saved as 100% Jpeg with IrfanView.)

As it can be easily seen, the in-camera JPEG is obviously sharper, with higher resolution and contains more details. It wins hands down against the RAW converted image, which is also much larger in file size.

Just for more information, the original image was taken in Natural Custom Image mode in Saturation -1, Hue 0, Contrast +1, Fine Sharpness -1. The same settings have been automatically carried forward to the PPL by default. In order to confirm it is not a difference in the level of *sharpening* (generally called "Sharpness" for DSLRs' setting). I have tried to convert the same PEF RAW file using the maximum "Sharpness" setting, i.e., +4, to see if it could help. Here is the 200% view crop:-

Well, as it has been well expected, it doesn't help.

So, the SilkyPix RAW conversion engine of the latest PPL is really poor. It provides poor per pixel sharpness which the camera has already captured. It's just a waste of resolution and image details with such RAW conversion. I think other 3rd party RAW conversion software should be used if anyone is intended to shoot RAW with Pentax DSLRs. The bundled RAW conversion software just produced JUNK!

But then the problems with those 3rd party RAW converters are that:
1. They need extra bucks;
2. Many times and many of them are not as colour correct and the reproduced colours are not as faithful;
3. The compatibility is not as good!

It is sad and ridiculous as the bundled RAW software should produce better pictures, like what the Canon DPP can do, unfortunately, the PPL doesn't. But yet fortunately, the in-camera JPEG engine of the Olive K-m is very good. And actually, it is excellent, I would say. So, I just wonder, why Pentax did not use their own RAW conversion algorithms used in the Olive K-m to do the RAW conversion, even for the PPL?

More unfortunately, the same Soft JPEGs are yet found in the two K-7 production units I tested before. So, many times I just wonder what Pentax people are doing actually? I hope that they are not really like too much those Soft JPEGs, no matter in-camera or RAW converted (and the algorithms)!

Those Softy things are really rather unfortunate for all Pentax users and actually for Pentax themselves. Overall, it is just a very disappointing thing! :-(

Last but not least, the SilkyPix is infamous to produce low resolution and per pixel sharpness actually, which was what Klaus of the PhotoZone found about when he tested different RAW converters quite sometimes ago (now, I'm afraid that Klaus has deleted the review as I am unable to find it at the PZ):-


He tested different Spatial Freqency Response of the RAW converted by different RAW converters using the Imatest.

But the evidence for its existence before:-

Update (7-30) - Raw Therapee 2.4 Shootout Added:

(Click to view in full: 100% crop, simple resizing to 200% (no re-sampling), saved as 100% Jpeg with IrfanView.)

As seen in the above, the resolution and details are now obviously better than what the PPL 3.6 would deliver but still it is not as good as the in-camera JPEG owing to the more serious pixelisation resulted.

Also, the colour rendition and white balance are somewhat different than what in-camera JPEG and the PPL produces (more yellowish), as I have mentioned last time, the colour reproduction by third party RAW converters will not be as Faithful and would be less accurate.

Moreover, the RT Release Version 2.4 has compatibility issue or bug with K-m's RAW files. The program will crash each time when the RAW files are read in thumbnails. So, thanks to the hint by one of the above Blog pal who replied, I downloaded and tried the RC2 of the Version 2.4 instead and everything works fine. The interface of the RT is not so straightforward and direct for some of the key operations but the most serious problem of it I think is that it is very slow - both the DPP and PPL surely runs faster on the same PC machines that I use. It is an usable piece of software, though, and it is the only Free Standalone RAW converter that supports the Pentax DSLRs outthere (almost, AFAIK)!

In fact, the older versions of the Pentax Photo Lab (2.X etc.) were sharper, I just wonder why what is going on by now, actually?

Also, there is a little update regarding PhotoZone's RAW comparison links and report (which were changed), here they are:-



Thursday, July 16, 2009

K-m Olive Vs 5D Pixel Peeping

Since last time I pixel peeped the K-7 Vs the 5D, the same methodology and the same two Pentax lenses are used again to measurbate! But this time is my new K-m Olive Vs my old 5D.

The following pictures have been taken at almost the same time and at the same place:-

K-m Olive:


The test conditions and camera settings are as follows:-

K-m Olive: Factory default settings unless otherwise specified, Bright Custom Image (Saturation -2, Hue 0, Contrast 0, Fine Sharpness 0), Av exposure mode at f/8, FA 28/2.8 (Photodo MTF Score 3.8), AF-S, ISO 100, direct in-camera JPEG, all EXIF data preserved.

5D: Factory default settings unless otherwise specified, Faithful Picture Style (Sharpness 3, Contrast 0, Saturation 0, Tone 0), Av exposure mode at f/8, FA 43/1.9 Limited (Photodo MTF Score 3.6), MF according to EOS's focus indication, ISO 100, direct in-camera JPEG, all EXIF data preserved.

The Field/Angle of View of Both Cameras are the Same.

The following are the 100% crops from the above two pictures, with 5D's crops further downsized to 88% (linear) to the same viewing size for easier comparison:-

K-m Olive Crop 1:

5D Crop 1:

K-m Olive Crop 2:

5D Crop 2:

K-m Olive Crop 3:

5D Crop 3:

Well, I think the K-m Olive images are obviously having a higher image fidelity than those from the production K-7 (actually I tested two units - no difference) and it approaches the level of details of the 5D at low ISO, whilst the K-7 has not much improvement even at the lowest ISO speed of 100. Nevertheless, the K-m images at Sharpness 0 are having a higher level of sharpening than that of 5D (which is ranged from 0 to 7, 3 is just less than the middle, but I had to opt). But no matter how, the resolution is preserved and the image details are there, for both cameras.

And, you may note about the colour differences of the two pictures from my 5D and K-m. Actually, the 5D produces a bit more accurate colours but the K-m's one seems looking a bit more attractive. The real scene is somewhere in between, but more close to the 5D's one. (The reality usually are not as beautiful, believe me! That's why some people don't want to see the truth! ;-D )

As a short final remark, for what I have used/tested the K-m before, the in-camera Jpegs are not as detailed, but yet still better than the K-7, I am afraid and very honestly speaking. It seems that the new Samsung sensor inside the K-7 would be the true limiting factor here, otherwise the K-7 would have been much better. But without good PQ/IQ, what's the point of a "better" camera?? (At the end of the days, I am afraid that the PQ/IQ of the K20D could be even better! Oh, No... :-()

Wednesday, July 15, 2009

K-m Olive Colour Matching


K-7 Strange Vertical Line Repeatedly Shows Up, Found by Different Users

Further to my last reports on the K-7 Vertical Line Bug, the first lot of german users are starting to complain about the vertical line in the K-7 images as well:-


Look at Post #2948 by "theNewGuy". To view the attached pictures, registration is required. It is a grasshopper shot. There is a lighter vertical light across the grasshopper, mostly more obvious on the back of the grasshopper against the dark background.

Well, I think this is a common known bug now, possibly is a problem of the new Samsung sensor. Would Hoya/Samsung react and rectify the problem? When? Soon or forever.. NOT?

Tuesday, July 14, 2009

My K-7 Hands On Test and Findings

A full production unit was tested and my observations and findings are as follows:-


1. Autofocus is fast (not with SDM, which is slow by itself): With the 18-55 WR kit lens, it has been able to track moving vehicles running at speeds at about 30 to 40 km/hr at middle to close distances. Used in conjunction with the Continuous Hi frame advance mode, the shooting rate can be kept at about 3 to 4 fps and the AF hit rate was high (only the Central Single AF point was selected for the test);

2. Shutter is very quiet (but not so smooth). Mirror action is very gentle, too;

3. Shutter lag is shortest for a Pentax DSLR ever (similar to Canon 5D but obviously still not as short as the D300 or 50D etc., nothing comparable to the EOS 1 series DSLRs);

4. Rigid, lightweight and compact body, well balanced in hands, very comfortable to hold for the grip - very good ergonomics;

5. Flash raised at a high position and pop-up action is smooth and gentle. The closed RTF is rigid and there is no play;

6. Auto WB accuracy and reliability seems to have been improved - the best amongst any Pentax DSLRs ever.


1. It does not feel metalic for the metal alloy body - very different from the MZ-S. Actually, Pentax can make it plastic as the metal alloy shell actually doesn't feel cold nor it has any metal feel and texture. The K-m might even feel better, IMHO;

2. Shutter/mirror action is not silky smooth as it can feel and heard for the "rough" moving sound;

3. Viewfinder is near 100%, but it is not that bright (even a F2.8 prime was mounted) and the magnification is not that high - Still some kinds of tunnel viewing effect is there, nothing comparably to Full Frame DSLR viewfinders;

4. The 77-segment metering is too conservative and too sensitive: It counts too much for the bright area(s) anywhere in the frame. Whenever there are highlights, even those areas are small and they are off-centre, the picture will be underexposed! (The K-m 16 segment metering works better!);

5. AF seems not to be as accurate as it should be, especially for an APS-C DSLR with that pixel count, which might contribute to the soft images obtained as resolution of even sharp optics are decreased (but not the main reason, I suspect, read more below);

6. The expensive WR kit lens is of low optical performance. Blurs are too obvious at corners near wide opened (not extreme corners). The image centre is not tack sharp neither, even at closed down;

7. Images are blurry, in-camera Jpegs are very soft throughout the frame;

8. Images are noisy, at least two stops disadvantages than the 5D and surely will be even more if it is compared to the current mainstream Full Frame DSLRs like the D700 and 5D MkII;

9. LCD display is always turned on "to ease operations" by default which is considered unnecessary but just a waste of battery power, especially considered this is an advanced classed camera, not an entry level one without top monochrome status LCD;

10. Mode dial unlock button hinder operations and is considered unnecessary. The button is small and turning mode dial whilst pressing it is somehow difficult;

11. Colours are a bit too saturated and somehow look unnatural than real even for the Natural image mode used, might be a result of underexposure which produces more saturated images. But it also seems that the Samsung CMOS sensor produces images that look less favourable than those Sony or Canon sensors (that can be somehow subjective anyway).

12. Video function is buggy, there is sudden flash (drastic change in exposure) for a short clip I recorded without any good reason. CDAF under LiveView / Video recording is damn slooow. It hunted a lot very slowly and sometimes even missed the focus and needed to search again.

13. The video quality of the movie is just so-so. I shot in 720p mode. What I have to say it is not better than the 848x480 H.264 Movie from my Casio Exlim S10 and I would say the playback of the S10 movies could just be smoother.

I suspect the reason for the Soft JPEGs is yet once again not because of inadequate processing power of the camera, but inherently a noisy sensor (the new Samsung one) of which the images it produces are needed for in-camera noise reduction and as a result the images are made soft. This is the same as what Photography BLOG's test shows: You could get Either Soft JPEGs Or Noisy RAWs (with details but together with noises), even at ISO 200, with the K-7. Trade-off and compromise have to be taken.

Okay, last but not least, here comes some sample images (100% Crops from in-camera Jpegs, 5D's ones further upscaled by 115% (in area) in IrfanViewer for almost the same viewing sizes, saved as lossless 24-bit BMPs):-

Camera / ISO
Scene 1
Image Centre
Scene 1
Image Corner
K-7 / ISO 100

5D / ISO 100
K-7 / ISO 200

5D / ISO 200
K-7 / ISO 400
5D / ISO 400
K-7 / ISO 800
5D / ISO 800
K-7 / ISO 1600
5D / ISO 1600

Camera / ISOScene 2
Image Centre
Scene 2
Image Corner
K-7 / ISO 100
5D / ISO 100
K-7 / ISO 200
5D / ISO 200
K-7 / ISO 400
5D / ISO 400
K-7 / ISO 800
5D / ISO 800
K-7 / ISO 1600
5D / ISO 1600

Remarks on the test conditions:-

K-7: Factory Default Settings, "Natural" Custom Image, Matrix Metering (No Exposure Compensation), ISO NR starts at ISO 800, Medium setting, AF-S with Central Single AF point selected, no frame re-composition after AF achieved, FA 28 (Photodo MTF Score 3.8) @ f/8;

5D: Factory Default Settings, "Faithful" Picture Style, Matrix Metering (No Exposure Compensation), no ISO NR, MF with Central AF point selected, no frame re-composition after focusing point measured, FA 43 (Photodo MTF Score 3.6) @ f/8.

Field/Angle of View of both Cameras are the Same.

I have repeated similar tests with my new K-m and the results against my 5D is not of such a huge difference! It verifies that the K-m produces sharper images with more details and less noise even for the same viewing/zoom-in sizes, with more favourable colour response, too. My Olive DAL kit lens is also way sharper than that WR version which triple the price of an ordinary DAL 18-55, too.

Btw, I shall do a more systematic shootout test and post the results later on - K-m Vs 5D, when I have the time. Update: Here is the test - K-m Vs 5D Pixel Peeping!